JPS5937395A - Vacuum heat-insulating type fluid transport pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] It is something.

It is very often desirable to transport a fluid at a temperature different from the ambient temperature from one location to another with a limited amount of heat exchange between the fluid and the ambient atmosphere.

For example, warm petroleum gas and/or 'liquids may need to be flowed through pipes located under extremely cold conditions. An excessive reduction in fluid temperature results in an increase in its viscosity to such an extent that economical flow is difficult or impossible. Furthermore, if the pipe is passed through a permafrost zone, there is a risk that the permafrost will melt due to heat radiation and its mechanical support will be lost.

District heating requires the transport of heated water throughout a region of users located within a distance from a central heat source, such as a power plant or geothermal field.

Chemical processing processes require transporting various fluids at very high temperatures during their conversion to the final product.

The economics of these processes depends, among other things, on the degree to which heat dissipation is prevented.

Another case where the heat exchange between the fluid being transported in a pipeline and the environment must be reduced as much as possible is the transport of refrigerants and other cryogenic liquids or liquefied gases. Such cryogenic liquids may be used, for example, in superconducting power lines or magnets, and may function as fuel in rocket propulsion.

Whatever the nature or purpose of the fluid, some form of insulation must be provided around the pipes transporting the fluid.

Laminates of insulating materials such as foamed plastic, asbestos or glass fibers have been proposed, but these are easily soaked with water and lose their insulating capacity.

Their mechanical resistance is very poor and they are therefore easily damaged during shipping or rough handling.

The use of vacuum as an insulating medium was proposed. This can be achieved through the use of two concentric tubes, where the inner tube is used to transport fluid and the jacket gaps of the inner and outer tubes are evacuated. For example, U.S. Patent No. 1.
See No. 140.653. The use of vacuum insulation has been found to be very effective in significantly reducing heat exchange between the transported liquid and the surrounding atmosphere, but the vacuum must be kept low enough to maintain the integrity of the insulation for a sufficiently long period of time. Found it difficult to maintain pressure. The vacuum after evacuation is approximately 10-') #(t3X10-2Pa) ~10
-' Torr ('L 3 X 10' Pa), the heat exchange between the inner and outer walls by heat transfer and convection becomes significant. Continuous release of adsorbed gas from metal surfaces exposed to vacuum increases the pressure and ultimately destroys the thermal insulation properties of the structure. In theory, it would be possible to re-evacuate the space in time intervals of This is unrealistic considering that they are often located in different locations and are often buried underground.

In an attempt to maintain the required degree of vacuum, it is well known that zeolites tend to sorb gases, so placing zeolites within the vacuum space, such as in U.S. Pat. No. 3,369,826, It was suggested that. Unfortunately, in order for zeolites to have any appreciable gas sorption properties, they must be cooled to low temperatures. In addition, water vapor is preferentially sorbed by the zeolite, which early prevents the sorption of other gases by the zeolite.

Upon increasing the temperature, the sorbed gas is released.

Charcoal and PdO are also covered by U.S. Patent No. 5,992,1.
As suggested in No. 69, PdQ can only sorb H2. Furthermore, palladium is expensive.

It is therefore necessary to provide some means for continuously maintaining a vacuum within the pipe interior space for extended periods of time without requiring human intervention or the use of expensive additional equipment.

The dosing must be done so that the temperature increases required during the preparation of the tube do not result in changes in the metallographic phase that alter its physical or mechanical properties.

It is therefore an object of the present invention to provide a more efficient and reliable fluid transport pipeline member and method for making the same, which does not have the disadvantages of previously known fluid transport pipeline members.

Another object of the invention is to provide a vacuum adiabatic fluid transport system in which a satisfactory degree of vacuum is maintained for a considerable period of time by the use of a getter material capable of permanently sorbing active gases and allowing reversible sorption of hydrogen. An object of the present invention is to provide a pipeline member.

Another object of the invention is to provide a fluid transport pipeline member and method of making the same that does not result in metallographic phase changes of the metals used in its construction.

The present invention will be explained in detail below. Referring now to the drawings, FIG. 1 shows a first fluid pipeline member 1
02 and similar pipeline members 104, 106 connected at both ends thereof. In the illustrated embodiment, pipeline member 10
2 includes an inner metal tube 108 of cylindrical form and a substantially concentric outer metal tube 110 also of cylindrical form. A first coupling means in the form of a metal 7 flange 112 connects the inner and outer tubes 108.
．． Adjacent first ends 114 and 116 of 110 are welded to each other in a vacuum-tight manner. A second coupling means in the form of a metal 7 flange 118 is welded to the second adjacent ends 120.122 of the inner and outer tubes 108.110, respectively, in a vacuum-tight manner.

This structure defines an enclosed space or jacket 124 that is evacuated by a valve (not shown) or other means, as described below.

The first and twenty-seventh flange coupling means 112.118 may be bolted in a fluid-tight manner to similar seven flanges in each of the additional pipeline members 104.10 (S). In the illustrated embodiment, the gaskets 126.126' ,
126"1126"' ensures the tightness of the connections between the pipeline members.

The flanges 112 , 118 each have a central hole 128 , 130 having a diameter approximately equal to the inner diameter of the inner tube 108 . This allows continuous fluid flow through the inner metal tube. A getter device 132 containing a non-evaporable getter material 134 is in thermal contact with a wall within jacket 124, in this case an inner wall 136 of outer metal tube 110. The getter material is one that is capable of permanently sorbing active gas and reversibly sorbing hydrogen.

The getter device may take any suitable form for maintaining thermal contact with the walls within the jacket, such as as a powder applied directly to the walls using a binder or as individual pellets. A continuous metal strip with getter powder compacts bonded to one or both sides can also be used.

A preferred form of getter device 200 is shown in FIGS. 2 and 3 and consists of a continuous length of thin metal IJ tube 202. The strip has depressions at regular intervals 204.204
1, etc. are formed and filled with non-evaporable getter material 206, thus providing getter material support zones 208, 208', etc. The zone 210 of the metal strip between five adjacent getter material support zones includes every other bending zone 21.
A slit 212 can be formed if desired to provide 4.

These allow the strip to be easily contoured along the curvature of the jacket wall while maintaining sufficient thermal contact.

4 and 5 illustrate another preferred embodiment 400 of a getter device for use in the present invention. In a continuous length of thin metal strip 402 , getter material support zones 404 use strips of material from curved zones 406 to stand them upright to form walls 408 of each support zone 404 .

In use, an IJ tube of the required length is cut and placed in contact with the exterior or interior walls of the inner and outer tubes 110 within the jacket as shown in FIGS. 6.7 and 8. Getter material 206 is exposed to the interior space as shown in one enlarged view of FIG.

The getter material used is any non-evaporable getter material that can provide permanent sorption of active gas and reversible sorption of hydrogen. Preferably, the non-evaporable getter material is (a) an alloy of zirconium and aluminum with an aluminum weight percent of 5 to 30%; (bl Zr, Ta, Hf, Nb, Ti,
Partially sintered mixture of at least one metal powder selected from the group consisting of Th and U and carbon powder present in an amount up to 30% by weight; fc) l) consisting of 5 to 30% by weight AI-balance Zr Granular Zr-A1 alloy and ii) Zr, Ta, Hf
.

Partially sintered mixture of at least one granular metal powder selected from the group consisting of Nh, Tr, Th and U; -V -Fe When plotting on the ternary composition diagram 1) 75% Zr -20% V -5% F'e
1i) 454 Zr -20%V -55% Ii
'eiff) 45%Zr -50% V -5%
Zr-V-Ti'e powder alloy falling in the band having the point defined by Ii''e as a corner point; (el l
) at least one granular metal selected from the group consisting of Ti and Zr;
-When plotting on the Fe ternary composition diagram I) 75%Zr -20%V-5%Fe++)
45% Zr -20%V -654Pe1ii)
Zr −V − falling in the band having the point defined by 45%Zr −50%V −5%Fe as a corner point
Selected from the group consisting of partially sintered mixtures with Fe powder alloys.

The pipeline member is preferably fitted with expandable means for absorbing differences in thermal expansion or contraction between the inner and outer pipes, and seven langes or member joining means are provided to accommodate the difference in thermal expansion or contraction between the inner and outer pipes. It will be appreciated that these aspects may be designed to minimize heat transfer, but these features do not form part of the present invention.

In fabricating the fluid transport pipeline member of the present invention, a first end of the inner metal tube and adjacent first ends of the substantially coaxial outer metal tube are vacuum-tightly attached to the first connecting means by welding. be done. Both tubes are preferably cylindrical and the coupling means are preferably seven flanges suitable for fluid-tight coupling to additional pipeline members so as to provide continuous fluid flow through the inner tube. Inserted into the space between the inner and outer tubes is a non-evaporable getter device, which may conveniently be in the form of a thin metal IJ tube supporting a getter material as described above.

If the pipeline is intended for the transport of warm or hot fluids, it is advantageous to place the strip in thermal contact Ic with the inner metal tube so that the getter material is maintained at a suitable temperature during fluid transport.

The temperature of the fluid may even be high enough to activate certain getter materials. This is the case when the fluid is a high pressure flow at a temperature of about 30Q to 450°C, thereby raising the temperature of the non-evaporable getter to about 10:00K. If the fluid to be transported is a cryogenic fluid, the IJ tube should be placed in thermal contact with the inner wall of the outer metal tube, thereby maintaining the getter material at ambient temperature during fluid flow. .

After inserting the getter device into the space between the inner and outer tubes, the second end of the inner metal tube and the second end of the outer metal tube are attached in a vacuum-tight manner to the coupling means, which is preferably also a flange. After that, the jacket space is 1o-21le (1,3Pa
) or less, preferably 10-4 Torr (13X10-2
Pa) is evacuated to a pressure below. While the jacket space remains evacuated, the pipeline member is heated to a temperature greater than 150°C, preferably about 250°C or higher. This temperature should be maintained for several hours to degas the jacket surface. The jacket is then sealed and disconnected from the vacuum pump system. If the getter material is such that it is activated at low temperatures, the degassing process described above is sufficient to activate the getter material. If this temperature is not high enough to activate the getter material sufficiently, the area of the pipe in which the getter device is located can be heated from outside the jacket. This may be achieved by any suitable means, such as by exposure of a flame over the surface, or by induction heating in a suitable zone. If the inner tube surface of the jacket is plated with a metal such as zinc to provide a more highly reflective surface and thus improve jacket insulation, the zone in which the getter material is supported is preferably unplated. should be left in.

A preferred method of making pipeline members is to accomplish most of the steps in a vacuum oven. A first end of the inner metal tube and substantially coaxial adjacent first ends of the outer metal tube are attached in a vacuum-tight manner to the first coupling means by welding. Both tubes are preferably cylindrical and the coupling means is preferably a flange suitable for being coupled in a fluid-tight manner to an additional pipeline member to allow continuous fluid flow through the inner tube. . The inner and outer tubes coupled to the first coupling means are placed in a vacuum oven together with the second coupling means.

If the getter material can be fully activated under the temperature one hour conditions used for degassing the tube in a vacuum oven,
It is convenient to insert a getter into the space between the inner and outer tubes before placing the assembly in the vacuum oven. In this case, the getter device is arranged in a first
It may be arranged near the coupling means. If the getter material requires a relatively high activation temperature to be heated so that it can sorb gas, the getter device can be placed in a vacuum oven separately from the tube and the second coupling means.

After evacuating the oven and heating its storage element to the degassing temperature, the getter device is separately heated to its activation temperature by suitable means such as induction heating and placed in the space between the posterior inner and outer tubes. . At the end of the degassing, the second end of the inner metal tube and the second end of the outer metal tube are vacuum-tightly joined, such as by electron beam welding, to a second fitting means, preferably also a seven flange. After the second flange connection to create the vacuum jacket, the pipeline member is allowed to cool and removed from the vacuum opening.

Although the present invention has been specifically described above, it should be remembered that many modifications may be made within the spirit of the invention.

[Brief explanation of drawings]

FIG. 1 is a sectional view of three connected parts of the vacuum insulated fluid transport pipe member of the present invention, FIG. 2 is a plan view of a getter device useful in the present invention, and FIG. 3 is 3-3 in FIG. Fig. 4 is a plan view of another getter device, Fig. 5 is a sectional view taken along line 5-5 in Fig. 4, and Fig. 6 is a getter device attached to the outer tube. Figure 7 is an enlarged detailed view of the part marked with a circle in Figure 6, and Figure 8 is an end view of the pipeline member being manufactured, showing the getter device in the inner tube. It is. 100: Pipeline assembly 102.104.106: Pipeline member 108:
Inner tube 110: Outer tube 126.1261.1261'31261'=Gasket 152: Getter device 134: Getter material 200: Getter device 202: Metal strip 204.204': Recess 206: Getter material 208.208' Nigeta material support zone 214: Curvature band FIG, I FIG, 3

Claims (1)

Claims: 1) an inner metal tube, a substantially coaxial outer metal tube, and first means for joining first adjacent ends of the inner and outer tubes in a vacuum-tight manner; second means for joining second adjacent ends of the outer tube in a vacuum-tight manner, the inner and outer tubes and the first and second means defining an exhaust jacket;
In a fluid transport pipeline member, wherein the first and second means are adapted to join the pipeline members together in a fluid-tight manner and to permit continuous fluid flow through the inner tube, A fluid transport pipe member characterized in that a non-evaporable getter material enabling sorption and reversible sorption of hydrogen is disposed in thermal contact with a wall within the jacket. 2) A knob member according to claim 1, wherein the non-evaporable getter material is supported by a metal strip. 3) an inner metal cylindrical tube and a substantially coaxial outer metal cylindrical tube;
a first metal flange that connects first adjacent ends of the inner and outer cylindrical tubes in a vacuum-tight manner; and a second metal flange that connects second adjacent ends of the inner and outer cylindrical tubes in a vacuum-tight manner. a metal flange, the inner and outer tubes and first and second flanges define an exhaust jacket, the first and second flanges fluid-tightly joining the pipeline members together; In a fluid transport pipeline member adapted to permit continuous fluid flow through the tube, a getter device is disposed in thermal contact with the inner wall of the outer tube, the getter devices forming alternating bending zones. and a getter material support zone, and a non-evaporable getter material which allows permanent sorption of active gases and reversible sorption of hydrogen. Pipe members described in section. 4) an inner metal cylindrical tube, a substantially coaxial outer metal cylindrical tube, a first metal 7 flange joining first adjacent ends of the inner and outer cylindrical tubes in a vacuum-tight manner, and the inner and outer metal cylindrical tubes; a second metal flange joining second adjacent ends of the tube in a vacuum-tight manner, the inner and outer tubes and the first and second flanges defining an exhaust jacket; and a second flange adapted to join the pipeline members in a fluid-tight manner and permit continuous fluid flow through the inner tube, wherein the getter device is connected to an outer wall of the inner tube. A thin metal strip disposed in thermal contact, the getter device comprising alternating banding zones and getter material support zones, and a non-evaporable metal strip allowing permanent sorption of active gases and reversible sorption of hydrogen. The pipe member according to claim 1, characterized in that the pipe member is composed of a getter material. 5) The getter material is (al) an alloy of zirconium and aluminum with an aluminum weight% of 5 to 30%; (bl) Zr, Ta, j-1f, Nb, T
Partially sintered mixture of at least one metal powder selected from the group consisting of i, Th and U and carbon powder present in an amount of up to 30% by weight; (cl i) 5 to 30% by weight A , I-remainder Z1'
ii) a granular Zr-A1 alloy consisting of Zr,
Ta, l-1f. A partially sintered mixture of at least one granular powder selected from the group consisting of Nb, T'+-, Th and U; Table 1. When the composition is plotted on the Zr -V -Fe ternary composition diagram 1) 75% Zr -20%V -5% Fe+1
) 45%Zr -20%V -55% Fe1ii
) 45%Zr - 50%V - 5%Zr -V falling in the band having as corner points the points defined by
-1)'e powder alloy; (el l) Ti and Z
at least one particulate metal selected from the group consisting of r; Time j) 75% Zr -20% V -5% Fe1
t) 45%Zr -20%V -35%Fef
! t) 45% Zr -50% V -5% F
A pipe member according to claim 1, wherein the pipe member is selected from the group consisting of partially sintered mixtures of Zr-V-Fe powder alloys falling in a zone having corner points defined by e. 6) A method of making a fluid transport pipeline member, the method comprising: (A) attaching a first end of an inner metal tube and an adjacent first end of a substantially coaxial outer metal tube to a first coupling means; (n) inserting a non-evaporable getter material into the space between the inner and outer metal tubes, which enables permanent sorption of active gas and reversible sorption of hydrogen; evacuating the space between the outer metal tubes; +Di heating the inner and outer tubes to a temperature above 150°C; 7) The method of claim 6, wherein the steps are in the order A, B, E, C%D. 8) A method according to claim 6, wherein the getter material is heated to a temperature below that which causes a phase change in the tube metal to enable its gas sorption. 9) Claims in which the sequence of steps is A, B, E, C, D, after which the getter material is heated to a temperature lower than that which causes a phase change in the tube metal to enable its gas sorption. The method described in Scope Item 8. 10) A method of making a fluid transport pipeline member, the method comprising: connecting a first end of an Al cylindrical inner metal tube and a first end of a cylindrical outer metal tube with continuous fluid flow through the cylindrical inner metal tube; vacuum-tightly welding to a first flange suitable for fluid-tight joining of pipeline members together to allow FB+ an outer wall of the inner metal tube in the space between the inner and outer metal; Insert a non-evaporable getter device in thermal contact with the getter device, where the getter device includes a thin metal tube with a bending zone and a getter material support zone (IJ tube) and the getter material provides permanent sorption of active gas and hydrogen. and (at alloy of zirconium and aluminum with aluminum weight % from 5 to 30%; (bl Zr, 1'a, Hf1Nb, Ti,
Partially sintered mixture of at least one metal powder selected from the group consisting of l'b and U and carbon powder present in an amount of up to 30% by weight; 1 cll) consisting of 5 to 50% by weight A1 - balance Zr Granular Zr-A, 1 alloy and if) Zr) 'l'a
>l-1f. Partially sintered mixture of at least one granular metal powder selected from the group consisting of Nb vTi%Tb and U; When plotting on Zr -V -Fe ternary composition diagram l) 75% Z, r -2n% V -5% Fe
1f) 45%;', r -20%V -35%F
e1iD 45%Zr - 5o%V - Zr falling in the band having the point defined by s%Fe as a corner point
-V -Fe powder alloy; tel) Ti and Z
at least one granular metal selected from the group consisting of When plotting l) 759bZr -20%V -5%11"ei
i) 45% Zr -20% ■-35%
Fe1ii) 45%Zr -so%V -s%FN
(Q) said inner and outer metal tube 2) heating the limb to a temperature of 150° C. or higher; vacuum on a second flange suitable for fluid-tightly joining the pipeline members together to permit continuous fluid flow through the tubular inner metal tube; 11) The method of claim 10, wherein the order of steps is A, B, E, C, D. 12) The method of claim 10, wherein the getter material is heated to a temperature at which a phase change occurs in the metal of the inner metal tube to enable gas sorption. 13) The method of claim 12, wherein the order of steps is A, B, E, C, DSF. 14) A method according to claim 10, wherein the getter device is attached in thermal contact to the inner wall of the outer metal tube. 15) The method of claim 12, wherein the inner surface of the outer metal tube and/or the outer surface of the inner metal tube, except for the getter material support zone, is metal plated with a reflective surface. 16) A method of making a fluid transport pipeline member, the method comprising: (A) connecting a first end of a cylindrical inner metal tube and a first end of a cylindrical outer metal tube with continuous fluid flow through the cylindrical inner metal tube; vacuum-tightly welding the inner metal pipe to a 17th flange suitable for fluid-tight joining of pipeline members to allow for fluid-tight connection; A non-evaporable getter device is inserted in thermal contact with the outer wall of the thin metal tube (IJ) with a bending zone and a getter material support zone, the getter device comprising an IJ tube and a getter material for permanent sorption of active gas. An alloy of zirconium and aluminum that allows reversible sorption of hydrogen and has a fat aluminum weight ratio of 5 to 60%; (bl Zr, 'ra, Hf,, Nb,
Partially sintered mixture of at least one metal powder selected from the group consisting of Ti, 71'b and U and carbon powder present in an amount up to 30% by weight; (cll)s ~ 30% by weight AI = balance Granular Zr-A1 alloy consisting of Zr and jj) Zr, Ta, If
. (d) a partially sintered mixture of at least one granular metal powder selected from the group consisting of Nb, i'i, Th and U; (d) a Zr-V-Fe powder alloy, expressed in % by weight; When the composition is plotted in the ternary composition diagram Zr -V -F”e 1) 75% Zr - 20% V - 5% 1,000 1eii) 4
5% Zr -20%■-35%Fetii) a5
%Zr -50% V -5% Zr -V -Fe falling in the band having the point defined by Fe as a corner point
Powder alloy; (el i) at least one granular metal selected from the group consisting of Ti and Zr; i) Z,
r-V-Fe powder alloy whose composition expressed in weight percent is plotted on the Zr-V-Fe ternary composition diagram: 1) 75% Zr - 20% V - 5% FeIt)
45% Zr -20% V -35% Ii'etii
) 45%Zr -50%V -5% Zr -V falling in the band having the point defined by Fe as the corner point
- a partially sintered mixture with Fe powder alloy;
a step of evacuation to a pressure of less than or equal to Pa); a step of heating the former limb to a temperature of 150° C. or more; welding in a vacuum-tight manner to a second flange suitable for joining pipeline members in a fluid-tight manner to enable continuous fluid flow through the cylindrical inner metal tube; activating the non-evaporable getter device by flowing superatmospheric steam at a temperature of 450° F. through the inner tube to heat the non-evaporable getter device to about the same temperature.